Field of Invention
The present invention relates to an alarm apparatus containing security and safety monitors. More specifically, the present invention relates to a single alarm apparatus being capable of detecting unauthorized opening of doors and windows, of detecting fierce knocking on windows and doors and of detecting abnormally high temperature.
Related Prior Art
Conventionally, separate devices are respectively used for detecting unauthorized opening of doors and windows, for detecting fierce knocking on doors and windows and for detecting abnormally high temperature. However, there has not been any single apparatus providing both the above-mentioned functions. Therefore, the present invention is intended to provide a compact apparatus for providing the above-mentioned functions.
Furthermore, electromagnetic devices have been used for detecting fierce knocking on doors. Such an electromagnetic device has a magnet attached on a door and a sensor mounted on a wall. When the door is fiercely knocked, the magnet is sufficiently moved so that the sensor senses the change of magnetic field. Thus, the movement of the magnetism, i.e., the violent knocking on the door, is detected. However, when such a device is used for monitoring doors made of iron or steel, the doors will be induced with permanent magnet after being used for a period of time. Thus, the accuracy of such a device is affected. Therefore, the present invention is intended to solve this problem.